Grinding-machine.



v No. 839,080.

- PATENTED DEC 18, 1906. c. O. SMITH. GRINDING MACHINE. APPLICATION FILED 00T.31, 1904. RENEWED 001 22, 190G.

3 SHEETS-SHEET 2.

\ UNITED STA-WENT OFFICE.

. CLAYTON O. SMITH.,OF WORCESTER, MASSACHUSETTS. ASSIGNORTO NORTON EMERY WHEEL COMPANY, OF WORCESTER, MASSAOHU SETTS.

nols'saoso.

GI R INDING- M ACH INE.

Patented Dec. 18, 1906.

' Application filed October 31, 1904. Renewed October 22, I906. Serial No. 340,072.

l leretofore, so far as I am aware, it'ha been customary to grind ball-races for the:

purpose of giving them their desired contour y means of a shaped emery or abrasive.

wheel-that is, an emery-wheel having a grinding-face of shape which it is desired to give to the ball-race; Another wellknown" method of securing the desired contour of the ball-raceis to employ pattern guide-plates, by means of which devices governing the bodily movement of the grinding-wheel are led over the attern and the grinding-wheel thereby bodi y moved from one oint to an other of the surface to be groun The first of these methods necessitates the repeated repairing or truing up of the grinding-wheel, as is obvious, while the second necessitates a useless and complex multiplicity of expensive parts which entail a constant expense for their renewal and repairs.

In the present invention I obviate both the necessity of requiring a shaped wheelfor grinding ball-races and the use of attern guide-slides by somOunting; the a 'rasive wheel that the. portion of the abrasive face thereof which engages the .work can be moved in a curvillnear path whiletin contact with the work and at the same timeithat thewheel is rotating about its axis, the contour ofthe path corres onding to the cross-sec tional contour of t e ball-race.

' In the preferred form of my invention I mount the abrasive wheel to swingabout an means for oscillating the wheel about saidaxis having-an angular relation to the axis about which said wheel rotates and provide axis during the grinding operation. Thiscauscs that portion of the abrasive face of said wheel which engages the work to swing back and forth in the arcof a circle, and by giving sald wheel-a rotary motion about its axis and at the same time the swinging motion above referred to the desir ed contour the shape-of the face of the wheel.

In the accompanying drawings, Figure 1 is a rear view of a machine embodying my invention. Fig. 2 isa side View thereof. Fig. 3 is a top plan view. Fig. 4 shows details of the traversing. mechanism for the carriage which supports the abrasive wheel. is a cletal mav, be given the ball-race without regardzto of the shoe forming a part of the traversin mechanism. Fig. i 6 is a view 1g. 7 is a'front view of an annu- 4 lus having a ball-race ground therein.'

showing t e rinciple on which my inventi on operates.

Referring first to Figs. 6 and 7, which show an annulus having-a ball-race ground therein, 3' designates said annulus having a ball-race 4 in one face thereof, said ball-race'constituting the way in which the balls'of a ball-bearing travel when this part is assembled with the other parts constituting said ball-bearing. It is necessary, of course, that the cross-sectional curvature of said ball-race should be a true are ofa circle, and to give saidball-race this desired contour I mount the emery or abrasive wheel, which is shown in edged view at 5, Fig. 6, so that said wheel can swing bodily about an axis having an angular relation to its axis of rotation. In

this embodiment of my invention the axis about which the abrasive wheel swings bodily stands at right angles to the axis of rotation of said wheel, and in Fig. 6 is designated b .the point 6, which point also coincides'wit the center of the arc of curvature of the ballobvious that if the abrasive w eel 5 is s from the full-line positionto the dotted-line position about the axis'6at the same time that said wheel is rotated about its own axis the ball-race will be ground on the arc of 'a circle whose center is the point 6, regardless .race 4. Referring to said Fi 6, it will be of the sha e orcontour of the face of the abrasive w eel.

In the embodiment of my invention shown in Figs. 1, 2, and .3, the abrasive .wheel 5 is mounted in suitable bearings 7, carried by a wheel-stand 8; said stand in turn being sup ported by a carriage 9, suitably supported upon the frame 10. of the machine to turn a out the point 10'as an axis. The carriage 9 may be oscillated about its axis 10 by any suitable means, that herein shown compris ing an endless screw 11, journaled in suitablel hearings in the frame 10.- Cooperating laterally thereof.

with the groove 12 of said screw is a shoe 13, which is j ournaled in a block 14, mounted to slide in suitable ways 15 in the frame. Pivoted to said block 14 is a link 16, which is also pivotally connected with the carriage 9, as at 17. With this construction it will be obvious that rotation of the endless screw 11 will cause the shoe 13 to traverse back and forth in the groove 12, and the movement of said shoe through the link 16 will oscillate the carriage 9 about its axis 10. 51 designates a guard which is carried by the block 14 and operates as a cover for the guideway in which the block 14 moves. This form of traverse mechanism for the carriage is not essential, however, and any other suitable means for oscillating said carriage maybe used without departing from the invention.

I prefer to adjustably mount the wheelstand 8 upon the carriage 9, thereby making the machine capable of adjustment for grinding ball-race grooves of different sizes, as will be more fully explained hereinafter. The adjustment of the wheel-stand 8 upon the carriage may be effected in any suitable or usual way, as by an adjusting-screw 18, having a hand-wheel 19 thereon, by means of which said wheel-stand may be adjusted.

My improved machine also includes a suitable work-support on which is supported the piece or element in which the ball-race is to be round. The particular construction of wor -support may be varied according to the shape of the piece to be supported thereby. In the em odiment of my invention herein-illustrated the work-support is adapted to sustain an annulussuch as shown in Figs. 6 and 7, and it comprises a suitable chuck device 20 0f. any appropriate construction, adapted to hold said annulus 3. This chuck device is ri id therewith and is driven by a gear 21, mes in with a pinion 22 upon a shaft 23,,said shaft aving a driving-pulley 24 thereon and being mounted in suitable hearings in a stand 25. The-work-holder is preferably adjustable both toward and from the abrasive wheel and laterally withrespect thereto, and forthis purpose I have mountedthe stand 25 to slide on ways 26-on a carriage 27, and said carriage in turn is mounted to slide on suitable ways 28 on the mainframe 10*. The ways 26 28 are arranged at right angles to eachother, thus permitting the work-holder to have the desired movement toward and from the'abrasive wheel and also Any suitable or usual ad.- justing-screws 29 and 30 are provided for adjusting the carriage 27 on its ways and the stand 25 on said carriage.

The shaft carrying the endless screw 11 and also the shaft 23 for driving the chuck device may be driven in any suitable way.

As herein illustrated they are driven fromthe same power-shaft, and for this (purpose said power-shaft, WlllCll 1s designate has thereon a pulley 32, which is belted to a pulley 33, carried by the shaft 34, on which said endless screw 11 is mounted, and said power-shaft also has thereon another pulley 36, which is belted to and drives a pulley 37, fast on said shaft 23. I prefer to mount the pulley 33 loosely on the shaft 34 and to provide suitable clutch mechanism 38 for clutching said pulley to the shaft at the appropriate time. Any other way i of driving the shafts 34 and 23 may be employed, however, without departing from my invention.

I have herein shown my machine as equipped with any suitable or usual pum) mechanism 40 for delivcrin water through the pipe 41 to the abrasive wheel for keeping said wheel cool. The abrasive wheel may be driven in any suitable way, such as by means of belt 44, connected to some overhead shafting.

In grinding a ball-race in an annulus, such as shown in.Figs. 6 and 7, said annulus is first clamped to the chuck device 20, and the face 48, in which the ball-raceis to be ground, is trued up on the abrasive wheel by moving the stand 25 back and forth upon the ways 26 and at the same time rotating said chuck device. During this operation the clutch 38 is disengaged, and therefore the carria e 9 has no oscillatory movement, and the a rasive wheel may have any desired position, although I prefer to place it substantially in the position shown in Fig. 3. After the face 48 has been trued up the carriage 27 is ad justed so as to position said face a distance from the axis 10 equal to the length of radius of the curvature of the ball-race to be ground minus the de )th of said ball-race. In practice these bal -races are usually ground to the depth of one-eighth of an inch, and therefore the work-support is adjusted so as to bring the face 48 a distance from said axis 10 e ual to the radius of the curvature of the desired ball-race less oneeighth of an inch. As-

suming that the ball-race is to be ground on an arc of a circle whose radius is three-quarters of an inch, the work-support will be adjusted. to bring the face 48 thre'esquarters of an inch minus one-eighth of an inch, or fiveeighths of an inch from the axis 10. The

stand 25 is then adjusted upon the carriage 27 to move the annulus laterally to bring the face thereof opposite the abrasive wheel, and said abrasive wheel is then adjusted until the ortion thereof which engages the work will be projected beyond the axis 10 a distance equal to the radius of curvature of the desired ball-race. The machine is then'set into operation and the clutch 38 thrown into en-' and the rotation of the shaft 23 will cause the annulus to turn about its axis. 'llhese coml)lll((l movements result 111 grmdmg the ballrace t'o-the desired curvature, as seen in Fi 6 and 7 and this curvature is obtained wit out any regard .to the exact contour ofithe face of th grinding-wheel. It is unnecessary, therefore, to be constantly truing the abrasive wheel, and the grinding operation can be proceeded with rapidly and with absolute certainty.

The-principal fe'atnre'of my invention is the mountin of the abrasive wheel so that it'will swing odily about an axis having an angular relation to its axis of-rotation,vthere-,

' by moving that portion of the abrasivei-ace thereof in a curvilinear path corres onding to .the curvilinear cross-section of t e ballrace to be round, and believing that I am the first to evise a machine having this feature I desire'to claim it broadly. The particular manner of mounting the wheel so as to obtain this-swinging movement, may be changed in various ways without departin yet my -thereby. 1

Having described my invention, what I claim as new, and desire to. secure by Letters Patent, is.

1.]In .-.a grinding-machine, an 'abrasive wheel and means to rotate said wheel simultaneousl in two intersectin planes of rotation'whi e the grinding portion ofthe wheel is engaging the work- 2. In a gri ding-machine, an abrasive wheeland se .arate means for simultaneously;

rotating sai wheel in. two planes of" rotation tive portion of -the-wheel is in engagement with'thework- .3. In 'a grinding-machine, anadjustablymounted abrasive wheel, :rota'ting means therefor, and means to shift the 'position' of work, thereby movin the the wheel pivotally while in contact with the ortion of the wheel which engages t ewor in a curvilinear path. 4. In a grinding -'machine', an, abrasive wheel, rotating means therefor, and means to swing s'aidlwheel about an axis havin an angular relation to its axis'of rotation wdiile the wheel is-engagin' the work. I V

5. In a grin ing-machine, an abrasive wheel, rotating means therefor, 'meansato swing said wheel about an axis-having an angular. relation to its axis of rotation while said wheel engages the work and means to adjust said wheel relatively to the axis about which it swings.

6.- In arinding-machine, an abrasive wheel, rotating-means therefor, and means toswing said wheel about an axis at right angles to its axis of rotation while the wheel engages theworkt.

-7 In a ,grinding --machine, an abrasive wheel, rotating means therefor, means to swing said wheelbodily about an axis having an. angular relation to its axis of rotation U while the wheel is in engagement with the awo'rk andv means to'adjust said wheel toward and irom the axis about which it swings.

8.. In a grinding-machine, a 'carria e mounted to swing in the arc of a circ e,v

means for oscillating. said carriage, and an abrasivewheel mounted on said carriage to oscillate therewith, the oscillation of the carriage moving the portion of the face of said wheel which enga es the work in an arc of a circle while the w eel portion is in such enga'gement.

. 9. In a grinding-machine, a carriage, an

abrasive wheel -adjustably mounted upon. said carriage and means to move said car I riage in a curvilinear path while said abrasive wheel is in engagement with the work.

10. In .a grinding-machine, an oscillating carriage mounted to swing about an axis, an

abrasive wheel mounted on the carriage and ada ted to engage the work under operation whi e said carriage is being oscillated means to adjust said wheel with relation to the carriage toward and from the axis of oscillation ofhthe carriage, and rotating means for the w ee 11.. In a grinding machine, "a: carriage adapted to oscillate about an axis of oscillation, means to oscillate said carriage, said means including an endless screw, an abrasive wheel mounted on the carriage and rotatirig about an axis which has an angular relation to the axis of oscillation, an rotating p means for said wheel. at right angles to each other while the opera- 12. In a -grinding-machine, an abrasive whee1-,'m eans to rotate said wheel, means to swing said wheel about an axis having an angular relation to its axis of rotation while said wheel is in engagement with the work under operation a work-holder, and 'means for moving the same to advance the work with refere ence to the abrasive wheel. 13. In a grinding-machine, a work-holder,

an abrasive wheel, means to give the workholder and abrasive wheel a relative movement, and means to swing said wheel about an axishaving an angular relation-to its axis of rotation during the time that the wheel is in engagement with the work. 7

14. In a' grinding-machine, work-support,

.anabrasive. wheel, rotating means for said 'wheel, and-means toswing said wheel while inen'gagement with the work about an axis extending parallel to the face of the work on which said wheel is operating.

laterally with respect thereto.

an angular relation to its axis of rotation while the operating portion of the wheel is in engagement with the work a Work-support, and meansto adjust said work-support both toward and from said first-named axis, and

16. In a grinding-machine, a rotating work-holder, means for rotating said work holder, an abrasive wheel, rotating means therefor, and means to swing said wheel about an axis having an angular relation to the axis of rotation of the work-holder while the said abrasive wheel is engaging the work.

' 17. In a grinding-machine, a rotating work-holder, means to rotate said Workholder, an'abrasive wheel, rotating means therefor, and means to swing said wheel while in contact with the work about an axis at right angles to the axis of rotation of the work-holder.

Signed by me at Worcester, Massachusetts, this 26th day of October, 1904. i

CLAYTON 0. SMITH.

Witnesses:

F. H. LINCOLN, JOHN C. HILBURN. 

